Which BlockSize SSD Pool

We’ve an SSD pool and the initial Pool is created with 4K block sizes and the ZRAID is 10 with 12 disks.
Our VSMs is created with 4 K and the volumes is created a with record size of 8KB.
As we can see in the ElasticStore Graph the “Average Bblock size” is 8K.
The workload on the SSD Pool is 90% to run virtual machine on a XenServer with a Windows Server 2012 R2 OS.

Do you have any recommendations for us to saving space and still have enough performance, in terms of the pool/vsm block size and volume record size?
We already read the CloudByte Article about 4K Block sizes but at the and there is a recommendation to use 32K block sizes for the Pool – is this right?